The invention is concerned particularly with toothed gearing for the reduction of high speed drive motors, and more particularly concerned with electric tools, where at least one gearwheel meshes with a counter wheel or pinion and has a spur gear on or near its outer circumference. Gearwheels of this kind often include a coaxial trough for storage of grease.
A toothed gear of this kind is known from German Patent DE 41 12 843. There the coaxial trough of the gearwheel encloses a single storage chamber for the grease, and a lid of the trough is formed by a disc-like cover which adjoins a side of the gearwheel towards which the trough opens. In a contact area between this cover and a corresponding bearing face of the gearwheel there is one or more radially outwardly directed leakage path which can be formed by a hair gap between the contact bearing face of the gearwheel and the cover. During rotation of the gearwheel the grease located in the single storage chamber migrates as a result of centrifugal action towards the radial outlet gap and passes from there without further obstruction to lubricating points on the spur gear.
In practice with known toothed gearing grease in the storage chamber is used up too quickly. The lubricating action occurs even when the gearing is new and still has adequate lubrication as a result of lubricant which is applied directly to the spur gears of the gearwheels during its manufacture.